Normally-Off Schottky-Gate p-GaN HEMTs with Enhanced Irradiation Hardness

In this work, the p-type GaN layer (p-GaN) of the E-mode Schottky-gate GaN high electron mobility transistor (GaN HEMT) is patterned into designated segments, where one part of the p-GaN is buried with ohmic contact metal and connected to the source, while the other part serves as a real gate. This partitioned design of p-GaN can enable certain control of the channel by the source, and the gate is still functional. The threshold voltage (V
TH
) and ON-resistance
$(R_{\text{on}})$
of the resulting device are 3.64 V and 0.22 Ω respectively, as compared to the traditional structure device (3.37 V, 0.19 Ω). Furthermore, the proposed device exhibits decent gate breakdown capability and long-term reliability, revealing the functionality of this specific structure design. By carrying out ultraviolet (UV) pulse laser-induced single-event effect (SEE) irradiation experiments, the breakdown capability of the device under single-event burnout (SEB) conditions is significantly enhanced, which is attributed to the effective dissipation of radiation-induced holes by the constructed buried ohmic structure.